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When to Plant Serviceberries in Arapahoe County, CO

Arapahoe County, Colorado Zone 6a May

What to do in May

A quick May briefing for Arapahoe County, Colorado gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 10
Avg. first frost October 7
Soil temp (4") 37°F
Watering High
Pest pressure Low
Daylight 14.2 hrs
  1. Set out serviceberries seedlings

    Your last frost (May 10) has passed. These warm-season crops can handle outdoor soil now.

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Serviceberries (saskatoons) are attractive native shrubs or small trees producing sweet, blueberry-like fruits. They have beautiful spring flowers and vibrant fall color.

Arapahoe County, Colorado is in USDA Zone 6a. The average last spring frost is May 10 and the first fall frost is October 7, giving you a growing season of approximately 150 days.

At an elevation of 7,205 feet, Arapahoe County receives approximately 21.4 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Serviceberries during the growing season.

Arapahoe County, CO (Zone 6a) Moderate season
150 days
Last Spring Frost May 10
150 growing days
First Fall Frost October 7
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Arapahoe County Soil Profile

Soil Type

Loam

Soil pH

6.2-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: May 22
Recommended (50%) ✓ Fits season
Transplant: May 31
Safe Start (90%) ✓ Fits season
Transplant: Jun 12

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Arapahoe County

How your county's soil matches Serviceberries's growing requirements.

Soil pH

Your soil pH (6.2–8.3) is more alkaline than Serviceberries prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Arapahoe County is excellent for Serviceberries — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Serviceberries.

How to Plant Serviceberries

120"
Between Plants
144"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 642 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Serviceberries

Serviceberries needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Serviceberries Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 4.3" 2.5" 1.8" 💧 Light watering
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 2" 2.3" 🚿 Regular watering
Aug 4.3" 2.4" 1.9" 💧 Light watering
Sep 4.3" 1.9" 2.4" 🚿 Regular watering
Oct 4.3" 1.7" 2.6" 🚿 Regular watering
Nov 1.5" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Arapahoe County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Serviceberries Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Serviceberries needs ~13,916 GDD — county provides 2,287 GDD May not mature

Serviceberries Planting Timeline — Arapahoe County, CO

Serviceberries Planting Calendar

Activity When Date Range
Transplant Outdoors May 31 May 31 – Jun 14

· 120" apart · Rows 144" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
July
August
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

730–1095 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

150 days in Arapahoe County

Growing Tips for Serviceberries in Arapahoe County

Direct sow Serviceberries outdoors after May 10 in Arapahoe County when soil has warmed and frost danger has passed.

Your 150.0-day growing season in Arapahoe County is tight for Serviceberries (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.

Arapahoe County receives only 21" of rain annually. Serviceberries needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant in well-drained soil. Minimal pruning needed beyond removing dead wood. Protect fruit from birds with netting. Berries ripen in early summer and are excellent fresh or in pies.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Serviceberries in Arapahoe County, CO?

Arapahoe County is in Zone 6a with an average last frost of May 10. Plan your Serviceberries planting based on this frost date — see the calendar above for exact timing.

What planting zone is Arapahoe County, CO?

Arapahoe County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 10 and first fall frost is October 7.

🌱

Your Arapahoe County Garden Planner — Free

A 24-page printable planner built for Arapahoe County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Arapahoe County, CO. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.